Seat back rest support



Nov. 24, 1953 w. A. wmG

SEAT BACK REST SUPPORT Filed June 13, 1951 saw ' INVENTOR. Lly/vwaMQ,

A-r-rannav Patented Nov. 24, 1953 SEAT Bac REST SUPPORT William A. Wing,Milwaukee, Wis., assignor to Milsco Manufacturing CompanyyMilwaukee,Wis., a corporation of Wisconsin I I Application June 13,1951;;seria1'N6. 231,299'

2 Claims. (01. 155-1 7.

2 The invention, relates tose'ats and. more particularly. toanadjustable back rest.

. Themain object of theinvention i to provide a backrest support mountedfor angular adjustment relative to the seat by a hinge connec- Q l withthe seat frame, which connection includesa pair of radially toothed jawclutches whose clutch elements are angularly adjustable relative to eachother and adapted tobe clutched together by an operator controlledclamping means in the desired angular position of the backrest. relative,to the seat. The invention is of ,particular utility on tractorseatsand on seats for gunners in tanks. V U p The invention further'consistsin'the several features'hereinafter described and more particularly,defined by claims at the conclusion hereof.

In the drawings:

Fig. 1 is an elevation view of a seat structure provided with theinvention;

c Fig. 2 is a view similarto Fig. 1 showing a different formhoi seat;

Fig. 3 is an enlarged elevationview of parts of the seat structure shownin Fig. 1, parts beingibrokenaway and parts being shown insection; 1.Fig. 4 is a rear elevation view looking along the line 4-4 of Fig. 3;Fig. 5 is a View similar to Fig. 4 with the adjustable hinge in areleased position;

Fig. 6 is a detailed side elevation view of the side of the hingeconnection between the backrest support and the seat opposite to thatshown in Fig. 1;

' Fig. '7 is a detailed sectional view taken on the line 1-1 of Fig. 3;

Fig. 8 is a detailed side elevation view of one of the fixed clutchelements.

The seat with which the backrest support embodying the invention may beused may be of any suitable construction. In Fig. 1 I have shown abucket type seat including a metal seat body I0 provided with a cushionH of sponge rubber or other suitable materialhaving a top covering i2secured thereto, said body forming the seat frame and usually mounted ona suitable upright 13. In Fig. 2 I have shown a seat embodying a metalframe 14 and a seat cushion l5 mounted on this frame. In each instancespaced arms I 6 are formed as part of a U-shaped bracket [1 which issecured to the seat body or frameby bolts It or by welding or brazing orin any other suitable manner.

7 In each instance, a backrest cushionit is I mounted on a metal basemember 20 having a ,U-shaped bracket 2| ,(one side being shown)integrally secured or connected thereto, whose arms are pivotallyconnected by a bolt 22 to the upper end of a supporting upright whichincludes a square metal tube 23 which fits at its lower end in a squaresocket, 24; formed as a part of a hinge member 25 provided with spacedhinge arms 26 that are disposed between the arms l6 of the seat carriedbracket I1. A pivot bolt 27 passes through alined apertures in the armslfi and 26 so that the backrest support or upright may swing or tiltangularly relative totheseat. l V

' The invention hereinrelates to the hinge connection betweenthebackrest support and. the seatwhereby, the backrestsupportrnay betilted to different angularpositions relative to. the seat and besecured inthe desired .position.

Referring to Figs. 4' to 8, each of thehinge arms 26 has an angularlyadjustable clutch lock connection with the adjacent arm I6. For thispurpose each arm 26 has a clutch member 28 formed by a series of clutchteeth 29 radially extending from the hinge pin opening of said arm.'Thesetteeth' 29 are formed by displacing aportionv of. the metal of.the arm 26lat'erally into a die cavity by hydraulic pressure while themetal is annealed and then hardening the metal. Similarly, each arm l6has a cooperative clutch member 30 formed by a series of clutch teeth 3|radially extending from the hinge pin opening of said arm and formed inthe same way by a pressing operation and a hardening operation. Fig.8shows a front viewof one of the clutch members. The others are similar.

When the clutch members 28 and 30 are engaged, the teeth of theseelements intermesh with each other to form a strong clutch lock betweenthe 'arms26 and I6.

The clutch members 28 are held in a laterally fixed position by a metalsleeve 32 surrounding the pivot bolt 21 and abutting the arms 26. Acoiled torsion spring '33 surrounding the sleeve 32 hasone end 34engaging the member 25 and its other end 35 disposed in a hole 36 in oneofthe arms It so as to normally urge or swing the backrest supportforwardly toward the seat.

For locking the cooperative clutch members 28 and 30 together, means areprovided for springing or moving the arms [6 of the bracket .i'linwardly or toward each'other so as to bring the clutch parts intointermeshing relation. For

this purpose, a cam member 31 is pivotally connected .by a pin 38 to oneend of the hinge bolt 3 21 adjacent one of the arms I 6 while the head39 of said bolt is disposed adjacent the other arm IS. The cam member31, here shown as a forked member whose bifurcations are provided withcam surfaces 40, has an operating handle 41 connected thereto to form acamming lever whose surfaces 4B are moved into contact withthe outerface 42 of one of the arms 16 when said lever is swung upwardly to aclutch locking position, as shown in Fig. 4, this movement causin aninward lateral movement of the arms 16 due to the abutting engagement ofthe head 39 of the bolt and the surfaces 40 with said arms 1.6,

so that said arms l6 with their clutchesfifl are drawn toward each otherand into locking engagement with the cooperative relatively: fixedclutch members 28 on the backrest support. On the downward swingingmovement of the cam lever to the position shown in Figs. and 7 thenatural resiliencyof the metal forming the arms 16 causes 'them' tospring'apart to release the 'clutch elements so that the occupant of theseat may swin the backrest support backwardly against the action of 'thespring 33 to the desired angular position of the backrest and then lookthe backrest support in "this position by swinging the cam leverupwardly to the position shown in-Fig. 4; This adjustment may be madewhile the operator is in his seat. 7

To prevent free turning of the cam member with the pivot bolt'21, a stoplug 43j;is iormed as a part of one of the arms 16 and disposedat oneside of the cam member 31. Inpthe final locked position of the hingeparts'the high flat side lflaof' the cam: surfaces 40 abuts the outerface 421 of one. of the arms 116, thus limiting the final squeezebetween the parts.

. I.desire it, to be understood that thislinventi'on is.-not to belimitedto any particular form. or arrangement of'parts except in so farassuch limitations are included in the appended claims. What I claimasmyinvention is:

.1. -In-a seat structure having abackre'st supportehingedly connected tothe seat 'for'tiltable port 'hingedly connected to the seat for tiltableadjustment relative thereto, the hinge connection comprising thecombination of resilient spaced arms secured to the seat, spaced arms onthe backrest support, a pivot bolt extending through both sets of armsand having a head engaging one of said seat" arms, a'clutch. connectionbetween adjacen'tly disposed arms comprising intermeshing clutch teethradially disposed relative tosaid pivot member and integral with saidarms, andmeans forbringing said clutch teeth of each clutch connectioninto intermeshing locked connection comprising said pivot bolt and a cammember pivotally connected with saidbolt and engageable with the: otherof said. seatarms to flex said. seat arms toward the other set of arms,said cam. member having afflat surface engageable with said other seatarmlto. limit vthe final squeeze between saidseat arms. and the spacedarms of said backrest support. 7

WILLIAM A. WIN

References Cited in thefile ofcthispatent UNITED STATES" PATENTS NumberName Date 1,044,530 Hunn Nov. 19," 1912 FOREIGN PATENTS Number Country*Date 562,011 GreatBritain June 14, 1944 358,088 7 France Jan. 26, 1906

